Title page for ETD etd-10022008-063026

AMPS co-channel interference rejection techniques and their impact on system capacity

Degree

PhD

Department

Electrical Engineering

Advisory Committee

Advisor Name

Title

Reed, Jeffrey Hugh

Committee Chair

Bostian, Charles W.

Committee Member

Rappaport, Theodore S.

Committee Member

Ribbens, Calvin J.

Committee Member

Woerner, Brian D.

Committee Member

Keywords

wireless communications

AMPS

adaptive filtering

cyclostationarity

cellular capacity

interference rejection

Date of Defense

1996-07-05

Availability

restricted

Abstract

With the rapid and ubiquitous deployment of mobile communications in recent years, cochannel
interference has become a critical problem because of its impact on system capacity
and quality of service. The conventional approach to minimizing interference is
through better cell planning and design. Digital Signal Processing COSP) based interference
rejection techniques provide an alternative approach to minimize interference and
improve system capacity.

Single channel adaptive interference rejection techniques have long been used for enhancing
digitally modulated signals. However these techniques are not well suited for analog
mobile phone system (AMPS) and narrowband AMPS (NAMPS) signals because of the
large spectral overlap of the signals of interest with interfering signals and because of the
lack of a well defined signal structure that can be used to separate the signals.
Our research has created novel interference rejection techniques based on time-dependent
filtering which exploit spectral correlation characteristics exhibited by AMPS and
NAMPS signals. A mathematical analysis of the cyclostationary features of AMPS and
NAMPS signals is presented to help explain and analyze these techniques. Their performance
is investigated using both simulated and digitized data. The impact of these new
techniques on AMPS system capacity is also studied. The adaptive algorithms and structures
are refined to be robust in various channel environments and to be computationally
efficient.